1. Technical Field
The present invention generally relates to driving circuits for light-emitting diodes, and more particularly to a driving circuit for light-emitting diodes that can adjust the current through the light-emitting diode.
2. Description of Related Art
A typical driving circuit for a light-emitting diode uses a voltage source and a current-limiting resistor connected in series to drive the light-emitting diode. The current through the light-emitting diode changes, accordingly, the voltage across the light-emitting diode changes. The voltage source is adjusted linearly, however, the current through the light-emitting diode changes nonlinearly. If the voltage across the light-emitting diode changes more, the current may exceed rated current of the light-emitting diode, resulting in the light-emitting diode being damaged.
What is needed, therefore, is a driving circuit for light-emitting diode that can adjust the current through the light-emitting diode.